1. Field of the Invention
The present invention generally relates to a packaging method of thin film passive components on silicon chip, which employs ceramic or glass substrate to be mounted with the silicon chip so as to improve the mechanical strength of the component, and to a method of using thick film packaging technology to package the component.
2. Background of the Invention
In recent years, due to wide application of SMT technology, passive components are made into chips. Currently, thin film method and thick film method are essentially used to form passive components in the form of chips.
One such conventional thin film packaging method to form RC integrated component is disclosed in U.S. Pat. No. 5,355,014, wherein conventional semiconductor fabrication technology is used to form a RC network having Schottky diode on a silicon substrate.
Generally, after the formation of the thin film passive components, an insulating passivation layer is used to cover the components. Then, the conductive layer is exposed to provide a plurality of connecting points for soldering via photolithography and etching process. Then, conventional IC packaging method is used to package the products. Generally, this conventional packaging process includes the following steps: wafer backside polishing, wafer saw, die attaching, wire bonding, molding, marking, de junk/dam bar, lead cutting/forming, and packaging.
The thin film passive components fabricated by above-mentioned method has advantage of smaller size and higher yield. But, the cost is much higher than the similar thick film passive component. This is due to the fact that the process of packaging required by the thin film passive components is very complicated and the material cost is high.
If conventional thick film packaging method is employed, a passivation layer using screen printing, marking, cutting, termination, electroplating, and taping are required. The materials cost and process cost used in this method are less and the cycle time is shorter, thus, the total cost of packaging is lower.
However, the thin film passive components fabricated on the silicone substrates cannot be packaged by using such a method. This is because the silicon material does not possess sufficient mechanical strength and can be easily damaged in the fabrication process.
Accordingly, it is an object of the present invention to provide a packaging method of thin film passive components on a silicon chip, and employing a ceramic or glass substrate to bond with the component so as to improve the mechanical strength of the component. The present method employs thick film packaging method to package the component and solves the drawbacks described as above. The present invention also combines advantages of thin film process; such as better performance, smaller chip size with high yield, and thick film process; such as low cost packaging method.